Flashcards in Module 16: The Respiratory System Deck (48):
1
functions of respiratory system
continuous supply of oxygen for metabolic activities
Removal of CO2
Regulation of pH of blood
2
Processes of respiratory system
pulmonary ventilation
external respiration
transport of respiratory gases
internal respiration
3
Pulmonary ventilation
aka breathing in and out
4
External respiration
exchange of gases between blood and lungs
5
Transport of respiratory gases
gases are transported in RBC and blood plasma
6
Internal respiration
exchange of gases between blood and tissue cells
7
Structures of respiratory system (2 zones)
conducting zone (macroscopic)
respiratory zone (microscopic)
8
Conducting zone consists of
passageways for the conduction of air
nose
pharynx (throat)
Larynx (voice box)
Trachea (windpipe)
Bronchi
Terminal bronchioles
9
Functions of conducting zone - nose
Provides airway for respiration
moistens and warms air
cleans and filters unwanted particles
aids in speech
provides a sight for the olfactory receptors
10
Parts of the nose:
External nares: Nostrils, anterior portion is vestibule
Nasal cavities: separated by nasal septum; 3 bony projections called conchae; sticky mucus traps foreign particles
Internal nares: opening between nose and throat
Paranasal sinuses: maxillary, frontal, ethmoidal and sphenoidal sinuses
11
Pharynx
aka throat
consists of nasopharynx (air), oropharynx and laryngopharynx(food and air)
12
Larynx
aka voice box
contains vocal cords
connects pharynx to trachea
epiglottis covers opening of larynx
13
Trachea
aka windpipe
provides passageway for air to move in and out of lungs
Cleans warms and moistens incoming air
14
Bronchi
Trachea branches into left bronchus and right bronchus which lead to each lung
15
Terminal bronchioles
provide the passageway into the respiratory zone
16
Respiratory zone (microscopic)
respiratory bronchioles and alveolar ducts
17
Respiratory bronchioles
formed from branchings of the terminal bronchioles
18
Alveolar ducts
respiratory bronchioles lead into ducts
Ducts lead into clusters of alveoli
19
Alveoli (air sacs)
provide surface area for exchange of gases
found in clusters called alveolar sacs
20
3 types of cells in alveoli
Type I alveolar (simple squamous epithelium) provide site for gas exchange
Type II alveolar (septal cells) produce surfactant (compound that prevents alveoli from collapsing)
Macrophages (dust cells) clean up foreign material
21
Structure of the lungs
weigh 1kg
soft spongy and elastic
Take up all of thoracic cavity
Cone shaped
Each lung encased in pleura sac
base sits on diaphragm
22
Hilus
area in each lung where blood vessels, lymphatic vessels, nerves and the bronchus enter and leave the lung
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lobes in lungs
right lung has 3 lobes (55% of gas exchange)
left lung has 2 lobes (45% of gas exchange)
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Lobes of lungs are divided into
bronchopulmonary segments
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Lobules
small macroscopic subdivisions of bronchopulmonary segments
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2 layers of pleura
visceral layer hugs lung surface
Parietal layer lines thoracic wall and upper surface of diaphragm
27
During normal inhalation (inspiration)
thoracic volume increases
pressure in lungs decreases
28
During normal exhalation (expiration)
pressure in lungs increases and forces air out of the lungs
Thoracic volume decreases
29
Gas exchange in lungs
air inhaled
o2 from air diffuses from alveoli into capillaries
CO2 diffuses from capillaries into the alveoli
CO2 is exhaled
30
Gas exchange in body cells
oxygen leaves capillary blood and diffuses into the cells where it can be used during cellular metabolism
Co2 diffuses into the capillary blood as metabolism occurs in the cell
31
Transportation of oxygen
diffuses across alveoli into capillaries
O2 then dissolves in plasma
3% of O2 is transported as dissolved gas
97% of O2 is carried by Hb molecules
32
Transport of CO2
diffuses from tissue cells into capillaries
7% dissolved in plasma
23% with Hb in RBC
70% as bicarbonate ions in plasma
33
Medullary rhythmicity center
sets basic pattern of respiration
inspiration lasts 2 seconds
expiration lasts 3 seconds
normally 12-20 breaths per min in adult
20-40 in children
34
Chemical control of respiration
chemoreceptors are stimulated and relay messages to the brain
Central and peripheral
35
Central chemoreceptors
found in CNS (in medulla)
sensitive to increases in CO2 and H+ levels
36
Peripheral chemoreceptors
found in PNS (walls of carotid arteries and in aorta)
Detect decreases in oxygen levels
37
Factors that influence breathing
yawning
sneezing
coughing
hiccupping
crying
laughing
38
Bronchitis
inflammation of bronchial tubes
coughing up sputum
39
Laryngitis
inflammation of larynx
dry, sore throat with hoarse or no voice
40
Pneumonia
inflammation of lungs
inflamed lungs, high fever, cough, sputum with pus and blood
41
sinusitis
inflammation of sinuses
inflammation of paranasal cavities, headaches, pain, pressure in the bones of the face
42
Pharyngitis
Inflammation of the pharynx
sore throat and fever
43
Bacterial diseases
bronchitis
laryngitis
pneumonia
sinusitis
pharyngitis
44
Viral diseases
influenza
common cold
45
Respiratory distress syndrome (RDS)
aka Hyaline membrane disease (HMD)
most common cause of death in newborn
caused by deficient amount of surfactant
Difficulty breathing (exhausts the infant)
46
Lung cancer
accounts for 30% of all cancer deaths
most patients die within one year of diagnosis
85-90% of lung cancers are due to cigarette smoke
47
asthma
inflammatory disorder
narrowing of airways
coughing, difficulty breathing, wheezing
48